Accumulated Other Comprehensive Income (loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ 274,629	$ 294,142
Defined benefit pension plan [Abstract]
Net gain (loss) during year		(906)	769	$ (509)
Amortization of net loss	[1]	46	136	90
Defined benefit pension plan		(860)	905	(419)
Tax expense (benefit)		(238)	226	(105)
Total other comprehensive income (loss)		(622)	679	(314)
Ending balance		260,503	274,629	294,142
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(1,465)	(2,144)	(1,830)
Defined benefit pension plan [Abstract]
Ending balance		$ (2,087)	$ (1,465)	$ (2,144)

[1] These amounts are included in the computation of net periodic pension costs and were reclassified to selling, general and administrative costs.